Congenital ichthyoses, now grouped under the acronym EDD (Epidermal Differentiation Disorders), include nonsyndromic forms (nEDD) that may be caused by loss-of-function mutations in the CDSN gene encoding corneodesmosin (CDSN-nEDD, formerly Peeling skin syndrome type 1). This evidence concerns the gene CDSN and generalized peeling skin syndrome.